Coherence theory of truth
Encyclopedia
Coherence theory of truth regards truth as coherence with some specified set of sentences, propositions or beliefs. There is no single coherence theory of truth, but rather an assortment of perspectives that are commonly collected under this title. A positive tenet is the idea that truth is a property of whole systems of propositions and can be ascribed to individual propositions only derivatively according to their coherence with the whole. Where theorists differ is mainly on the question of whether coherence entails many possible true systems of beliefs or only a single absolute system. In general, then, truth requires a proper fit of elements within the whole system. Very often, though, coherence is taken to imply something more than simple formal coherence. For example, the coherence and coherence of the underlying set of concepts is considered to be critical factor in judging its coherence and validity.
(Quine & Ullian 1978). However, coherence theories of truth do not claim merely that coherence and consistency are important features of a theoretical system — they claim that these properties are sufficient to its truth.
According to another version of coherence theory, championed especially by H.H. Joachim, truth is a systematic coherence that involves more than logical consistency. In this view, a proposition is true to the extent that it is a necessary constituent of a systematically coherent whole. Others of this school of thought, for example, Brand Blanshard
, hold that this whole must be so interdependent that every element in it necessitates, and even entails, every other element. Exponents of this view infer that the most complete truth is a property solely of a unique coherent system, called the absolute, and that humanly knowable propositions and systems have a degree of truth that is proportionate to how fully they approximate this ideal. (Baylis 1962).
s in logic and mathematics. A claim like this needs to be qualified by the observation that formal reasoners are content to contemplate axiomatically independent
but mutually contradictory systems side by side, for example, the various alternative geometries. On the whole, coherence theories have been criticized as lacking justification in their application to other areas of truth, especially with respect to assertions about the natural world
, empirical
data in general, assertions about practical matters of psychology and society, especially when used without support from the other major theories of truth.
philosophers, especially Spinoza, Leibniz, and G.W.F. Hegel, along with the British philosopher F.H. Bradley. They have found a resurgence also among several proponents of logical positivism
, notably Otto Neurath
and Carl Hempel.
's. Russell maintained that since both a belief and its negation
will, individually, cohere with at least one set of beliefs, this means that contradictory beliefs can be shown to be true according to coherence theory, and therefore that the theory cannot work. However, what most coherence theorists are concerned with is not all possible beliefs, but the set of beliefs that people actually hold. The main problem for a coherence theory of truth, then, is how to specify just this particular set, given that the truth of which beliefs are actually held can only be determined by means of coherence.
Varieties of coherence theories
According to one view, the coherence theory of truth is the "theory of knowledge which maintains that truth is a property primarily applicable to any extensive body of consistent propositions, and derivatively applicable to any one proposition in such a system by virtue of its part in the system" (Benjamin 1962). Ideas like this are a part of the philosophical perspective known as theoretical holismHolism
Holism is the idea that all the properties of a given system cannot be determined or explained by its component parts alone...
(Quine & Ullian 1978). However, coherence theories of truth do not claim merely that coherence and consistency are important features of a theoretical system — they claim that these properties are sufficient to its truth.
According to another version of coherence theory, championed especially by H.H. Joachim, truth is a systematic coherence that involves more than logical consistency. In this view, a proposition is true to the extent that it is a necessary constituent of a systematically coherent whole. Others of this school of thought, for example, Brand Blanshard
Brand Blanshard
Percy Brand Blanshard was an American philosopher known primarily for his defense of reason. A powerful polemicist, by all accounts he comported himself with courtesy and grace in philosophical controversies and exemplified the "rational temper" he advocated.-Life:Brand Blanshard was born August...
, hold that this whole must be so interdependent that every element in it necessitates, and even entails, every other element. Exponents of this view infer that the most complete truth is a property solely of a unique coherent system, called the absolute, and that humanly knowable propositions and systems have a degree of truth that is proportionate to how fully they approximate this ideal. (Baylis 1962).
Coherence theories in specialized domains
Some versions of coherence theory have been claimed to characterize the essential and intrinsic properties of formal systemFormal system
In formal logic, a formal system consists of a formal language and a set of inference rules, used to derive an expression from one or more other premises that are antecedently supposed or derived . The axioms and rules may be called a deductive apparatus...
s in logic and mathematics. A claim like this needs to be qualified by the observation that formal reasoners are content to contemplate axiomatically independent
Independence (mathematical logic)
In mathematical logic, independence refers to the unprovability of a sentence from other sentences.A sentence σ is independent of a given first-order theory T if T neither proves nor refutes σ; that is, it is impossible to prove σ from T, and it is also impossible to prove from T that...
but mutually contradictory systems side by side, for example, the various alternative geometries. On the whole, coherence theories have been criticized as lacking justification in their application to other areas of truth, especially with respect to assertions about the natural world
Nature
Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...
, empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
data in general, assertions about practical matters of psychology and society, especially when used without support from the other major theories of truth.
Connections to other philosophical groups
Coherence theories distinguish the thought of continental rationalistRationalism
In epistemology and in its modern sense, rationalism is "any view appealing to reason as a source of knowledge or justification" . In more technical terms, it is a method or a theory "in which the criterion of the truth is not sensory but intellectual and deductive"...
philosophers, especially Spinoza, Leibniz, and G.W.F. Hegel, along with the British philosopher F.H. Bradley. They have found a resurgence also among several proponents of logical positivism
Logical positivism
Logical positivism is a philosophy that combines empiricism—the idea that observational evidence is indispensable for knowledge—with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions of epistemology.It may be considered as a type of analytic...
, notably Otto Neurath
Otto Neurath
Otto Neurath was an Austrian philosopher of science, sociologist, and political economist...
and Carl Hempel.
Objections to coherence theories
Perhaps the best-known objection to a coherence theory of truth is Bertrand RussellBertrand Russell
Bertrand Arthur William Russell, 3rd Earl Russell, OM, FRS was a British philosopher, logician, mathematician, historian, and social critic. At various points in his life he considered himself a liberal, a socialist, and a pacifist, but he also admitted that he had never been any of these things...
's. Russell maintained that since both a belief and its negation
Negation
In logic and mathematics, negation, also called logical complement, is an operation on propositions, truth values, or semantic values more generally. Intuitively, the negation of a proposition is true when that proposition is false, and vice versa. In classical logic negation is normally identified...
will, individually, cohere with at least one set of beliefs, this means that contradictory beliefs can be shown to be true according to coherence theory, and therefore that the theory cannot work. However, what most coherence theorists are concerned with is not all possible beliefs, but the set of beliefs that people actually hold. The main problem for a coherence theory of truth, then, is how to specify just this particular set, given that the truth of which beliefs are actually held can only be determined by means of coherence.
See also
- CoherentismCoherentismThere are two distinct types of coherentism. One refers to the coherence theory of truth. The other refers to the coherence theory of justification. The coherentist theory of justification characterizes epistemic justification as a property of a belief only if that belief is a member of a coherent...
- Confirmation holismConfirmation holismConfirmation holism, also called epistemological holism is the claim that a single scientific theory cannot be tested in isolation; a test of one theory always depends on other theories and hypotheses....